1. Field of the Invention
This invention relates to a direct drive water-driven rotary tool used for wet grinding, wet polishing, or wet sanding of many surfaces, including stone, cement, fiberglass, wood and metal surfaces, wherein the tool is used in a water filled or water containing environment, and specifically to an improved direct drive water-driven grinder and sander that eliminates the use of internal gears thereby reducing wear on internal bearings, has improved efficiency and reliability, creates higher torque and power and is easy to manipulate when in use.
2. Description of the Prior Art
Hydraulic driven rotational tools are known in the prior art. U.S. Pat. No. 1,905,424 issued to R. Schlieper, dated Apr. 25, 1933, shows a hydraulic driven washing apparatus which is a cleaning apparatus for cars that uses a garden hose to provide rotary motion to a sponge. U.S. Pat. No. 4,193,228 issued to Bowler, dated Mar. 18, 1980, provides a water-driven tool that can be used for polishing tile around a swimming pool or shower in a water environment. U.S. Pat. No. 4,463,525 issued to Sheber, dated Aug. 7, 1984, shows a hand-held cleaning tool with a remote water turbine power source contained in a floating housing. The outlet of the water turbine is connected to one end of a suction hose. A flexible drive cable assembly has one end connected to the cleaning tool and the other end connected to the water turbine. U.S. Pat. No. 5,620,364 issued to Torrance et al., dated Apr. 15, 1997, shows a hand-held water-driven rotary tool and uses water pressure to drive an internal gear and impeller to create the required torque.
One drawback of liquid-driven rotary tools shown in the prior art is that they do not produce sufficient torque to do a satisfactory grinding and sanding job. Another problem with the tools shown in the prior art is that they are awkward and uncomfortable to hold in position while in use.
The present invention overcomes these problems by providing a high torque water-driven sander and grinder. The device can be specially adapted for a plurality of uses within an already water filled environment such as a pool where it would not be practical to provide electrical power directly to the tool itself. Although electric motors do provide the high torque necessary for certain sanding and grinding operations, their use under water is totally impractical due to the dangers of electrocution and the inoperability of the motor in a totally enclosed environment. Therefore, the use of a high torque rotary power source for wet grinding or wet polishing of stones, cement, fiberglass and even wood and metal surfaces in a water filled or water containing environment is desirable. Such tools may be polishers, grinders, cutting tools, polishing and grinding disks, cutting disks and blades and possibly other uses for pumps, engines, cement mixes and grouts.
The present invention provides for high torque while at the same time providing a housing that includes a handle and trigger mechanism which allows for easy manipulation while the tool is being used, as well as providing ease of turning the device on and off.
In the device shown in U.S. Pat. No. 1,905,424 to R. Schlieper, the water impacting the turbine is deflected out through holes in sponges that are used to wash a vehicle. The disk shown in U.S. Pat. No. 4,193,228 to Bowler protrudes outwardly from the impeller housing and is disposed away from the housing itself. In the device shown in U.S. Pat. No. 5,620,364 to Torrance et al. ("the '364 patent"), a gear is locked and keyed to a centrally-mounted shaft so that as the gear is rotated by the impeller, the shaft also rotates causing the pad which retains the working disc to also rotate thereby allowing the device to operate. However, a major drawback of the '364 patent is the wear imparted upon the internal bearings due to the high speed of the rotating gear. The gear must rotate at 20,000 RPM to create the torque necessary to spin the cutting disc at 3,000 to 4,000 RPM, which is the required speed necessary to complete an ordinary job. The heat generated at 20,000 RPM tends to wear down the internal bearings which can ultimately lead to the bearing spinning faster than the shaft. This decreases the torque, creating cavitation, internal damage and insufficient performance.
In the present invention, the internal gears are eliminated, thereby reducing the number of internal parts and virtually eliminating damage to the bearings. The sanding disk or grinding disk is removably mounted to a backing pad in the housing for increased torque and mobility of the apparatus. The water used to drive the turbine is strategically diverted through a series of apertures so as to maximize torque created by the inlet water spray on the turbine allowing the sanding and grinding disk to operate to its full capacity.